4 research outputs found
The role of microglia in ischemic stroke
Cerebral ischemic stroke is a disease that belongs to the group of acute vascular disorders of the cerebral circulation. It is considered a major cause of disability and mortality worldwide. It has been shown that the integrity of the blood-brain barrier is impaired after an ischemic stroke, and this is the key factor in brain damage. An inflammatory reaction occurs, which is provoked and maintained by bioactive substances released by endothelial cells, brain glial cells, and blood immune cells. Microglial cells are the first to respond to an injury; they get activated through a series of molecular mechanisms and transformed into diverse functional subtypes. Activated microglia can have both aggravating and beneficial effects regarding tissue remodeling and recovery after ischemia. In addition to their functions, activated microglial cells also differ in their morphology, gene expression, and protein profile. Their type can also vary depending on the distance from the ischemic lesion. Microglial plasticity, as well as the complex relationships of microglia with other cells in the central nervous system under physiological conditions and after ischemic stroke, have been studied mainly in experimental animals: rodents and primates. However, more information has been generated by in vivo studies of post-stroke patients, applying highly specialized imaging methods. Nevertheless, the obtained results are insufficient and ambiguous, but they are a good basis for developing strategies to influence the recovery process after ischemic brain injury
Astrocyte heterogeneity under physiological conditions and after brain injury
There is a growing interest in astrocytes as glial cells in the central nervous system due to their important role in maintaining brain tissue homeostasis both under physiological conditions and after brain injury. A significant amount of evidence has been accumulated regarding their capacity to exert either pro-inflammatory or anti-inflammatory effects under different pathological conditions. In combination with their known high proliferative potential, they contribute not only to the limitation of brain damage and tissue remodeling but also to neuronal repair and the recovery of synaptic contacts in neurons. Moreover, reactive astroglia modulates the processes of neurogenesis, proliferation, and migration of neurons in the existing neural circuits in the adult brain. The identification of specific niche signals that regulate these sequential steps during adult neurogenesis may lead to the development of strategies for inducing functional neurogenesis in other areas of the brain after an injury or in degenerative neurological diseases
Postnatal cerebellar development in a mouse
The cerebellum is a part of the central nervous system, which plays an important role in cognitive functions, discriminative sensibility, and the coordination of voluntary movements. Its development takes place in two stages: prenatal and postnatal. The cerebellar germ originates from the rhombic lip. There are two major groups of cells: glutamatergic and GABAergic neurons, which are generated at different spatial-temporal intervals. In the postnatal period, Purkinje cells and their synaptic contacts undergo the most significant development. Another key point is the formation of anchoring centers and the foliation of the brain.The cerebellum is a part of the central nervous system, which plays an important role in cognitive functions, discriminative sensibility, and the coordination of voluntary movements. Its development takes place in two stages: prenatal and postnatal. The cerebellar germ originates from the rhombic lip. There are two major groups of cells: glutamatergic and GABAergic neurons, which are generated at different spatial-temporal intervals. In the postnatal period, Purkinje cells and their synaptic contacts undergo the most significant development. Another key point is the formation of anchoring centers and the foliation of the brain
Characterization of chilean copper slag smelting nineteenth century
El objetivo de este trabajo es caracterizar 4 escorias de fundiciones de cobre del siglo XIX, procedentes de vertederos abandonados en la Región de Atacama - Chile, utilizando las técnicas de fluorescencia de rayos X (FRX), difracción de rayos X (DRX), microscopía electrónica de barrido (SEM), análisis de partículas por difracción láser (ADL), espectrometría infrarroja por transformadas de Fourier (FTIR) y análisis termogravimétrico (ATG). Las escorias de cobre estudiadas fueron clasificadas químicamente como escorias ácidas, con mayor contenido de SiO2 (38 - 49%) que de Fe2O3 (18 - 37%), y con una importante cantidad de CaO (8-26%) y Al2O3 (5-8%). Su mineralogía y estructura es variada, presentando una de ellas una estructura amorfa y las tres restantes, una estructura cristalina con cierto carácter amorfo. Las fases inerales mayoritarias presentes en las escorias de cobre son diópsido, fayalita, magnetita, cristobalita y clinoferrosilita. Los niveles de calcio indicarían que las escorias poseen propiedades cementantes para ser utilizadas en materiales de construcción. Además, la importante cantidad de escoria disponible y el contenido de CuO (0,6 - 1,2%) muestran que puede ser de interés como materia prima en la recuperación del metal.Nazer, A.; Paya Bernabeu, JJ.; Borrachero Rosado, MV.; Monzó Balbuena, JM. (2016). Caracterizacion de escorias de cobre de fundiciones chilenas del siglo XIX. Revista de Metalurgia. 52(4). doi:10.3989/revmetalm.083S52